In the growth of children, child walkers provide a convenient means for an infant to be entertained, before, during, and after the transition from crawling to walking. Walkers provide support for a child in a seated position, but are readily movable by the child in a standing position. In the early learning, children have not the ability of controlling the direction of moving of walkers, which may go in the direction of uncertain manner, sometimes forward, sometimes backward, sometimes left, sometimes right. It is obvious that children can not choose the direction toward the dangerous area or toward the safe area under the situations described as foregoing.
Conventional walkers typically include a seat chair which is connected to the circular frame by supporting structure for supporting the child and some wheels located in the bottom of the circular frame. The number of wheels is not certain, it may be four wheels located at four corners of the frame or, more, six wheels. Conventional walkers can be freely oriented toward any directions through all non-directional wheels without constrains or brake arrangement. But it is very dangerous for children who are not able to control the direction of walkers yet. Accordingly, conventional walkers are generally provided with instructions and warnings to advise against the use of the walker without appropriate caregiver supervision, or against the use in the vicinity of floor edges, such as stair steps. However, these instructions and warnings, although practical and effective when followed, are not always observed. Therefore some terrible tipping accidents of the child walker occurred, especially when the child walker passes over an edge of a floor or the vicinity of stair steps.
An example of a conventional walker which attempts to respond to these concerns may be found in U.S. Pat. No. 5,813,681 ("the '681 patent") to Graco Children's Products Inc., issued Apr. 17, 1996. The '681 patent is to provide a child walker which has improved stability and resistance to tipping by including three wheels located in the relative position of triangle, in which two wheels are freely oriented and one wheel is constrained to move in a straight line to limit the direction of travel allowed by the child to maximize its stability. The '681 patent is to provide a child walker with immediate braking when the walker passes over an edge or a ledge. Besides, the '681 patent provides a child walker which can be adjusted by a caregiver to control the speed of the walker, and provides a rolling mechanism adapted for connection to a base member of a child walker to provide immediate braking or to limit the direction of travel of the child walker when the mechanism proceeds over an edge or a ledge.